1. Field of the Invention
This invention relates to a device to assist in testing and diagnosing problems in electronic integrated circuit flat packs which are soldered to a printed circuit board.
2. Description of the Prior Art
The widespread use of integrated circuit flat packs to perform various electronic functions has resulted in printed circuit boards having large numbers of these integrated circuit flat packs soldered thereon and spaced closely to each other. Consequently, whenever testing or diagnosis of malfunctions is desired, the technician has been confronted with the difficult task of using a test probe device to make contact with one particular electrical lead without touching other nearby electrical leads. Attempts to work directly on soldered leads with a single test probe have made troubleshooting on printed circuit boards densely populated by integrated circuit flat packs a difficult, time-consuming problem.
However, since the electronics industry has standardized integrated circuit flat pack dimensions and electrical lead configurations, efforts have been made to design a probe device which can be interchangeably clamped onto flat packs to provide convenient access to each electrical lead without the likelihood of inadvertent touching of a neighboring electrical lead.
The patent to Fisk et al (U.S. Pat. No. 4,055,800) discloses an important attempt to produce such a probe. This patent teaches that secure clamping of the test probe to an electronic flat pack may be achieved by using a unitary, multi-contact probe having pivotally, opposed jaws which can be placed over an electrical flat pack and mechanically secured. However, use of this test probe is a complex process involving rotating a knob on a clip until clamp elements can be manually compressed toward each other, thereby spreading the opposed jaws apart. The test probe is then placed onto an electrical flat pack, the clamp elements are released and the knob on the clip is rotated further until a cam thereon causes a lever to clamp the opposed jaws into a secure relationship with the flat pack. Moreover, since the jaws of Fisk do not include hooks, the test probe is held in place on an electrical flat pack only by lateral pressure and can be accidentally dislodged.
A number of other patents disclose attempted solutions to the problems associated with testing and diagnosing electrical flat packs, such as the U.S. patents to Luthi et al (No. 4,329,642), Dobarganes (No. 3,968,433), Beltz et al (No. 3,867,698) and Beltz et al (No. 3,803,709). However, each of these patents has failed to eliminate all of the problems solved by the invention disclosed herein. For example, the patent to Luthi et al (No. 4,329,642) does not enable testing of a flat pack which has been soldered into place, while the patent to Dobarganes (No. 3,968,433) discloses a test probe which may result in insecure fastening over a flat pack. The two patents to Beltz et al (Nos. 3,867,698 and 3,803,709) require critical manual dexterity in use and may result in precarious contact between the probe leads and the electrical leads of the flat pack.
Thus, it has remained an illusive goal in the integrated circuit flat pack test probe art to produce a test probe which is at the same time both simple to manufacture and easy to use while also resulting in a secure clamping of the probe to a flat pack.